A floor plan of a building, or other structure or space, is a representation or model thereof typically depicted as a view from above which may be embodied on paper or in electronic form, such as an electronic image or drawing. A floor plan defines and represents the boundary of the structure/space, referred to as the footprint, for example, as a polygon. A floor plan may further define and represent internal partitioning and/or compartmentalization of the interior, i.e. within the boundary/footprint, such as by depicting the position of walls, e.g. as lines, and other physical features. The floor plan may further represent dimensions and other absolute or relative characteristics of the structure/space through explicit notation and/or via proportional representations. Where a structure comprises multiple stories, levels or planes separating vertically defined spaces, e.g. floors, a floor plan for each floor, i.e. at each defined elevation, may be generated to depict the layout, unique or not, thereof and may include depictions of features, such as walls, elevator shafts, staircases, etc. shared between or otherwise common among multiple levels.
An exemplary structure is a shopping mall which may have, within its footprint, multiple partitioned spaces for retail establishments across multiple floors. Another example includes an office building having multiple floors partitioned into office space, common rooms, etc.
Floor plans serve many purposes. During the design of the structure/space, a floor plan may serve as a model or blueprint of the structure/space and used to plan and evaluate the design and facilitate construction thereof. Subsequent to construction, the floor plan may be used for remodeling or altering the design at later time. Further, the floor plan may used to generate maps of the structure/space which may be used to assist occupants/visitors in navigating between locations within, e.g. from an entrance to a particular office, store, bathroom, etc. Floor plans may further facilitate integration of a representation of the structure/space into a larger representation of an area in which structure space exists. For example, a regional geographic map may feature a representation of a shopping mall depicted at the geographic location thereof.
A floor plan may be created via free hand or other manual drawing techniques or using computer aided design (“CAD”) tools. In either case, for a given floor plan the designer draws representations of, for example, the exterior walls, interior partitions, elevators, staircases, doors, etc. When creating floor plans for multiple levels of a structure, the designer may define the floor plan of each successive level based on a representation of the floor plan of the prior level. For example, they may trace the footprint and common features from the prior level into the new level before then adding the unique features of that level.
While these techniques are straightforward and may result in highly accurate representations of a structure or space, they also suffer from problems. For example, the copying and/or tracing of features between levels can propagate and/or exaggerate design errors such as offsets between features which should be collinear among levels. Such errors may be introduced due to user error and/or due to imprecision in the representation of features, such as on a display screen, as compared with the actual characteristics of the actual physical features. For example, a representation on a computer display may inaccurately represent that two lines are drawn exactly on top of one another when in fact their positions are offset. This may occur due to the resolution or scale at which the computer generates the displayed representation as compared to dimensions of the feature represented thereby. Such errors may only become apparent when the floor plan is suitably manipulated, e.g. scaled or translated, and/or via a visual comparison between levels where, for example, subtle offsets may become visually perceptible. For example, when manipulating, such as scaling or translating, the floor plan of multiple levels for the purpose of creating a derivation thereof, e.g. navigational maps of the interior space, these errors may be revealed as incongruities between the levels and misrepresentations of relationships between locations.
In cartography, rubber-sheeting refers to the process by which a layer, such as a floor plan, may be distorted to allow it to be seamlessly joined to an adjacent geographic layer of matching imagery, such as satellite imagery (most commonly vector cartographic data) which are digital maps. This is sometimes referred to as image-to-vector conflation. Often this has to be done when layers created from adjacent map sheets are joined together. Rubber-sheeting is necessary because the imagery and the vector data will rarely match up correctly due to various reasons, such as the angle at which the image was taken, the curvature of the surface of the earth, minor movements in the imaging platform (such as a satellite or aircraft), and other errors in the imagery. Using floor plans created as described above, this process may reveal misalignments or incongruities or otherwise distort proportions resulting in less accurate or misleading representations.
Another problem with typical floor plan drawing techniques is the difficulty in making modifications or revisions. For example, where a designer wishes to modify a feature whose position may affect other features within a level or across levels, e.g. move an exterior wall, the designer must manually propagate the change to the affected features within the level or otherwise across levels. Propagation of changes is time consuming and affords additional opportunities to introduce errors into the floor plan and/or may reveal or exacerbate errors which were previously made.